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JAHA wonders: "I've seen two schools of thought regarding the proper method for charging an ipod so as to maximize the lifetime of the battery: let the iPod completely drain before re-charging; or keep the iPod completely charged as often as possible (i.e. leave it charging while you listen to it if you can). There doesn't seem to be any official word from Apple on their website, so I was hoping the smart people here could clear it up for me." For those looking for a definitive resource on the proper care and feeding of your iPod batteries, try this site.

Apple Ipods use Lithium Ion batteries, like a lot of portable products.

The lifetime of a rechargeable Lithium Ion battery shortens considerably if it is left 'topped up' on a charger for extended periods of time(weeks, etc). That's one of the reasons they are never used as backup sources of power.

One thing to consider is, if you leave it on the charger while listening to music, it will not be runing off of the power source, but rather the battery, which is constantly being charged, so it may reduce the life. I'm not certain on how their charging mechanism works, but this may be the case, in whiech, the parent is correct.

Depending on how the charging system works, that may or may not be relevant.

However, what MAY affect things is that I've noticed a great deal of iPods left connected to a mac do get very very hot.

One feature of a Lithium Ion battery is they age - and after around 3 years nearly every one made will be dead, it's just part of their chemistry. Heat drastically speeds up the ageing process in them, and I've no doubt that those iPods left connected and hot are killing their batteries.

I don't know what's causing it, whether it's a software bug that keeps the HD spinning, or an overcharging bug, or they're being used as a HD constantly, for an hour or more at a time, but that heat is damaging to battery life.

http://www.buchmann.ca/ has good lay-readable info about various battery technologies and their characteristics.

Actually, if you leave it connected long enough without accessing it, the hard disk in the iPod will spin down. (You may need to check the appropriate system preference.) I leave mine plugged in all the time, and every now and then I need to wait for it to spin up so I can access a file on it.

Apple does say (somewhere) that you should remove the iPod from any and all carrying cases when charging it, but so far I've ignored that too.

I actually used it as a scratch disk for downloading about 3GB the other d

Depending on how the charging system works, that may or may not be relevant.

The 'charging system' is, like almost all LiIon devices, managed by a dedicated IC. Go to Maxim's website- they have all sorts of chips specifically for this sort of thing. LiIon batteries pretty much can't be charged except by a very intelligent circuit. But yes, if you have a cheap charger on any other battery type, you will cause damage. Lead acid batteries are easily damaged if kept on an incorrect float current/voltage;

Apple knows the same thing that the rest of the computer industry does (as well as most car manufacturers)... if you make a product with a great feature set but limited life span, you make more money as people return to buy another. You just have to balance how long the life of the product is so that it is -just- long enough not to make the product seem "cheap".

I was in 2 different compu-shops this season buying gifts. In one shop a lady was yelling at the salesman because she could not g

Apple quite purposely made a disposable product with a life just long enough to keep people barely happy enough to buy again. As with computers, I think such products should have a government mandated company paid-for disposal program.

A simple way to replace the battery would fix the problem, but would lose Apple money.

-sigh- Just a little research, please? For $99, Apple will replace the battery and they will correctly dispose of the old one. Done.

Thanks, it is not a subject I have any need to take the time for since I own a different brand portable, but I will now correct the sales people when they mispeak if I hear it again. One of my more insipid vices:)

While invalidating alot of my angst:) you haven't changed the fact that the word is simply not out there among the masses.

I'll retract my original statement with glee, I'm always happy to see good ecological practices. However, Apple needs to edumuhcate the sales forces at their various retail

I think it speaks volumes against the "don't leave it plugged in" theory that Apple sells a dock which is designed to hold the thing all the time(and keep it charged all the time.)

I think the only thing it speaks volumes of is that Apple made a dock which is designed to make it easy to synchronize the iPod with the computer.
If you read any of the articles that were linked to in the initial post, you would see the lithium ion batteries have only two real enemies: time and heat. Full discharges do you no

Most quick chargers shut off or trickle charge the battery and are not harmful to the battery. I have many NiCads and LiIon batteries that have well over 500 charging cycles and some 10 years old that are almost as good as the day I bought them.

If you care for your batteries they will last a very long time and if you don't, they won't. It is as simple as that. The article mentioned tells the right way to do it....if you don't follow those guidelines don't whine when your battery is dead.

Battery research is focusing heavily on lithium chemistries, so much so that one could presume that all portable devices will be powered with lithium-ion batteries in the future. In many ways, lithium-ion is superior to nickel and lead-based chemistries and the applications for lithium-ion batteries are growing as a result.

lithium-ion has not yet fully matured and is being improved continuously. New metal and chemical combinations are being tried every six months to

Don't drain your batteries. Cells in a pack will discharge at different rates. When one dies and is driven in reverse by the other cells, it will be permanently killed. ESPECIALLY NiMH.

Memory effect is real, but you will not ever notice it, unless you do dozens of discharge cycles that are all the same length, to an accuracy of a few seconds. This isn't going to happen in normal use.

Basically, use your iPod. Charge it when you like. Don't run it all the way down.

It is noticed on Earth satellites that spend very regular cycles in sunlight/charging and darkness/discharging. If you listen to your Brittany Spears songs for EXACTLY 30 minutes, then charge your iPod, repeated for a few weeks, you'll get a memory effect. I doubt that many people would do that.

No battery likes being overcharged. NiCds handle it best, but it slowly eats away at them (assuming a slow charge.) Smart chargers will stop the overcharging, but most chargers for NiCd devices are not smart. So take them off the charger once the battery starts getting warm!

If they are overcharged, or never discharged fully, they'll start to show voltage depression (often mistakenly called memory.) A full discharge will usually resolve this, at least until the battery wears out.

NiMH cells are very like NiCds, but they have more capacity and handle abuse less well. They also don't suffer from voltage depression (often called memory) so there's no need to fully discharge them ever.

Never completely discharge either sort -- go down to 1.0 volts per cell and then stop. Going further can cause the weakest cell to be `reverse charged' making it even weaker. For normal users, this means just use the item until it needs to be charged, but don't just turn it on and leave it going overnight.

Li-Ion cells can *explode* if overcharged, so any decent charger will stop charging them before that happens. So they should be fine to leave on the charger forever.

They'll also die if fully discharged. Fortunately, most things that use them will turn off before this happens, for exactly that reason.

To be complete, lead-acid batteries (like used in your car) should not be overcharged, as it evaporates electrolyte. Good chargers will prevent this, and your car has a good charger in it. Do not leave them discharged for any length of time -- this will ruin them. Fortunately, they self-discharge very slowly, so they can be left alone for a year or so after a full charge and won't die (as long as there is no load.)

iPods and most laptops and cell phones have Li-Ion cells, though some older cell phones and laptops have NiMH cells (and even older ones may have NiCds.)

i hate to pick nits, but iPods and some PDA's have Lithium Ion Polymer [valence.com] batteries. Sadly, i don't know what properties Li-Ion Polymer batteries have verses standard Li-Ion cells, aside from the fact that Li-Ion Polymer is more of a flexible sheet rather then a AA shaped cell.

anyone have any more information? i know that the Li-Ion battery in my TiBook has seen a lot less memory effect in comparison to the Lithium Ion Polymer battery in my Clie. but then again, i keep my TiBook at a full charge most of the t

The memory effect present in Ni-Cd batteries is caused by crystals of Cadmium forming on either the anode or cathode (I don't remember which). The memory effect is not supposed to happen in NiMH batteries as there is no Cadmium in them. The high capacity NiMH batteries I have tell me to keep them topped off as much as possible to prolong their useful life.

Li-Ion batteries do not have a memory effect that I know of, so there shouldn't be a problem topping them off, but I haven't heard if this is good or bad

I have experienced problems with my iPod when I let it run down completely, it drops into 'zombie' mode and cannot be woken without unplugging the battery. This is a pain in the arse when I'm going to be away from my computer for a long time. The iPod is one of the first of the first generation and can now only hold charge for around an hour. I don't think that it'll make much difference how you do the charge/discharge dance, you just have to accept the fate that the battery dies. What we really want is sony to release the batteries to the general public (UK) so we can refit them cheaply ourselves.

I have a first generation iPod (it's about two years old now), and I actually listen to it until it tells me that it's out of battery/power before I recharge it. I have been doing this since day one, and it's been holding its charge fine. In fact, I don't even notice much battery degradation.

I too have a 1st gen iPod and have had no problems. Ok, i did, but that was solved by the update that corrected the power drain problem. If you thought you had a great lifetime on you battery and then put on the equalizer, shuffle and sound check, then THAT is the reason your battery is lasting all of 2 hrs.

quite simply, i think you must be doing something wrong if you are loosing you battery.

An iPod with a dead battery can still be plugged in to the wall. It might be possible to buy (or create) an external battery pack in which the electricity is converted from DC to AC and you could "plug it into" the battery pack. I'm not sure of this is possible, but if someone has setup something like this, perhaps using massive D sized batteries, you would never have to worry about the iPod's crappy battery ever again.

Of course this would ridiculously bloat the size of your iPod. The battery pack alone co

NiCds usually have less capacity than NiMH cells, but they last longer (more charge/discharge cycles.)

NiCd -- Needed to be fully charged and drained every single time.

No, not every time. Occasionally is good enough -- the more it's overcharged, the more often you'll need to fully discharge it.

NiMH cells do not show voltage depression (often called memory) so there's no need to worry about fully discharging them.

Li-Ion -- Hard on the battery if it's left full charged constantly.

No it's not. If the charger overcharges them, they could explode, so most chargers know when to stop. The real reason that people say not to leave them fully charged for long periods of time is that they can explode if accidently shorted out.

Li-ion cells are not at all forgiving -- if abused, they either die (fully discharged) or explode/burn (overcharged, short circuted.) It's the needed circuitry (to prevent these things from happening) that's forgiving.

Li-poly cells are more forgiving, but with most of the benefits of Li-ion cells. I don't know how popular they are outside of R/C applications, however.

Li-poly cells are more forgiving, but with most of the benefits of Li-ion cells. I don't know how popular they are outside of R/C applications, however.

And, of course, iPods. iPods are li-poly. They are only more forgiving in that if/when they explode or burn, you have a hunk of burning plastic rather than a pool of burning liquid. If they are physically damaged, there's no toxic fluid to leak everywhere.

The first generation was definitely li-poly. They have either changed, or Apple doesn't feel that they need to make the distinction. (Li-poly batteries are li-ion batteries, if I understand correctly. In li-poly batteries, the ions are in a polymer substrate rather than a liquid.)

It's damn near impossible to get the liquid li-ion batteries into something the size of an iPod. Most of the internal volume is occupied by the hard drive, leaving precious little for the battery. An advantage of li-poly batteries is that they can be made flat instead of round, which allows them to substantially reduce the external dimensions of iPods.

You're both wrong:) The first and second generation iPods were li-poly. They had problems with these, so they moved to lithium-ion batteries in the third generation iPod. The battery life went down from 10 hours to 8 hours in the process.

`Destroyed' isn't the right word. Damaged is a better term... of course, each time it happens it makes the weakest cell a little weaker, eventually making the pack as a whole almost unusable (due to that weak cell.)

I've not seen the iPod battery pack, but I suspect it's a 2 cell Li-poly. In that case, the unit should shut off long before either cell could ever be reverse charged. But it's definately a concern when you have more than 3 or so cells, and you have something that doesn't automatically sh

* Li-ion Longest life of most comercial batteries.
* Much harder to develop a memory. Most people it wwould take months.
* Hard on the battery if it's left full charged constantly.
* Still best if fully drained and charged every time, but very forgiving.

This is almost entirely wrong.

LiIon batteries have a maximum lifespan, aroudn 500 cycles. The deeper the discharge, the more "life" you use from the battery. Like lead-acid batteries, they are NOT forgiving of complete discharge and ch

What is the firewire cable to either my PowerBook, PowerMac, or do the wall plug that came with my 2nd generation 20 Gig iPod?

seriously though I have to say that everything I have that is Apple has been superior quality, I know some people get a bad apple from time to time, my friend had a PowerBook that just would not play nice, but overall the quality is better than other companies, its because of this pedestal they are on, that the few exceptions really stand out.

No.:)
He doesn't seem to be trying to be funny tho, or if he is he didnt do a particularly good job of it... Unless he was trying to make fun of us Apple types, in which case I feel I have the right to be offended...

I have a 20gb original iPod, with the non-moving wheel. I have had it for about 6 months. Before that it belonged to a friend, who rarely used it. Recently, it has developed a problem with the headphone socket. The sound from the left headphone is intermittent. I have tried using several different pairs of headphones, but the problem remains, so it looks like it's a problem with the contact inside the iPod rather than the headphones. I was wondering if any other slashdotters have had this problem, and if so

I've kept my rev A 10 GB ipod plugged in constantly for a couple of years--it's my main source of music at home and is plugged into my stereo at almost all times. But, on recent international flights, it has given me a solid 8 hours of music. I don't know why there is so much complaining about bad battery life.

Where I work I need to know a lot about rechargeable batteries. My impression of Li-ion / Li-Polymer is that they don't mind having a "float charge" at all... what the previous posts fail to mention is that for safety reasons, all Li-based chargers are intelligent enough to not overcharge the batteries (except cheap offshore chargers and car adapters, but you won't likely find anything like that for your ipod). In other words, I believe it is safe to leave an ipod plugged in indefinitely.

We picked up a battery analyzer from Cadex [cadex.com], which is really cool, and I use it every day.

But the really cool thing is that the charger came with a little paperback book called "Batteries in a Portable World", which offers a lot of insight into varying battery chemistries, even though it is sort of a pitch for Cadex products.

Nevertheless there is an online version of this book [buchmann.ca]. Go to chapter 2 and read up! There is some very valuable battery maintenance info in there -- if you own a single rechargeable battery it is a very good read. (The website asks for your email address, but you can probably just use a fake one).

I used to work at Radio Shack and did a very informal survey. Every time someone came in to buy a new battery for their cordless phone I asked how they cared for the phone and how long the battery lasted. In general, the more it was left on the charger, the shorter the life span. I broke down phone care into 3 groups:
1) Phone left on charger when not used. Battery lifespan was about 1 to 1 1/2 years.
2) Tried to keep phone on charger but forgot a lot. Lifespan about 2-3 years.
3) Kept phone off charger till the little light came on. Life span was 5 to 8 years.
These are pretty cheap batteries but the responses were pretty consistent. I also talked to people who bought standard rechargable batteries and rechargables for RC planes and cars. They answers and life spans matched pretty well.

Actually, I'm pretty sure that most if not all LiION batteries have a built in circuit that prevents serious overcharging or serious discharging. The danger is not from faulty chargers, but from defective battery packs or ones who's protection circuit may have failed.

That sounds right. It would certainly explain why offboard analyzers such as the Cadex unit I referred to seems to have trouble reading Li-ion batteries, because there is always a little circuit board in the battery pack with an IC on it... it probably fools the analyzer a lot of the time because it prevents it from seeing the cells directly.

Another interesting factoid: Lithium based cells are 3.6 volts, while NiCD and NiMH are 1.2 volts. Why ask why?:)

I've listened to all sorts of advice and have conducted limited experiments.

I believe the great unstated truth is that rechargeable batteries just plain have a limited life.

In fact, the lifetime on any one particular cell seems to be subject to a great deal of variation. For about ten years I tried to power all my AA, C, and D-cell-powered devices from rechargeable Nicads, and even when usage and recharging patterns were similar, some batteries _bought at the same time in the package_ might died after a year and a half, while others would be going strong after four years. I suspect this variation is one reason why manufacturers are so vague about lifetimes, and also contributes to peoples' superstitions (as they try to correlate the random behavior of individual cells with what they did to them.)

People who try to share rechargeable devices tend to bully each other and try to impose their personal superstitions about it ("I TOLD you not to keep it on the charger, Mabel!"), and companies who do not wish to replace dead batteries certainly are inclined to reinforce this. If I were a support person and someone phoned me with a battery issue, I would certainly suggest that they discharge the battery fully and recharge it. Why not? It would get them off the phone, and it MIGHT work, and when they called back to say it didn't it would be someone else's problem.

As for leaving batteries in the charger, at some point you have to assume that the people who make the batteries and the charger know what they're doing, and that the charger is smart enough not to deliver life-threatening quantities of charge to a fully charged battery. Certainly this should be true in these days where the chargers and batteries have microchips in them.

So I say, don't kick yourself over it. Accept the fact that rechargeable batteries are a) damn expensive, and b) only last a couple of years. Yes, it sucks, but lots of things do.

"Rechargeable" batteries sound as if they should last forever. So did "permanent needles" (ha! anyone else remember THOSE?), permanent waves, and permanent-press clothing.

I'm no battery expert, I don't even play one on the internet, but I can relate my own experience as a true early adopter.

I've got a 5 gig iPod purchased in Nov 2001. I use it at least 6 hours+ every day at work. I rarely use it on weekends. When it's not in use, it is on the charger (the AC adaptor, not hooked to my computer) - always, no exceptions.

It's now 26 months old and as far as I can tell the battery is almost as good as new.

So, my secret to success in a nutshell:
- almost never run it all the way down
- use it on a very regular basis
- always on the charger when not in use

Something I heard awhile ago, but haven't seen any discussion of is the importance of the *number* of charge/discharge cycles.
Li-Ion batteries are limited to about 1000 charge/discharge cycles. A cycle is defined as a switch between charging up and then discharging or vice-versa. Therefore, when you plug in your device to charge, -1 cycle. If you "use up" your cycles in 2 months by continually plugging & unplugging, so be it. Or over 3 years, same number of cycles.
This may explain the "left in charg

I had a problem a while back where my 2nd generation iPod (only a few months old) would lose it's charge completely overnight. So I took it to the genius bar at my local Apple store and determined that:

1) I was leaving my iPod in my car overnight (this was wintertime) and the iPod would 'freeze', which at the very least causes the iPod to *think* the battery is dead. (I wasn't clear if the battery was actually dead from freezing, or if the iPod just 'though' it was dead.) The only way to get it back to use